1. Field of the Invention
The present invention relates to a system and method for treating chronic pain through minimally invasive surgery. Particularly, the present invention is directed to a method and system for precisely locating a treatment location on the spinal cord using neuro-stimulation and then ablating the nerves of the spinal cord adjacent to the treatment area.
2. Description of Related Art
It is commonly known that pain persisting for more than three months, known as chronic pain, can be effectively treated with spinal cord stimulation (SCS). Spinal cord stimulation is currently performed with an implantable stimulation system consisting of an implantable pulse generator or two implantable lead systems having up to eight electrodes placed along the lead body. The lead system is electrically connected to the generator. The output of the generator is current controlled. A typical lead system has eight or sixteen channels that can deliver energy to as many as sixteen electrodes. The typical system also has one pulse generator and two lead systems connected in a dual head system to the pulse generator, each lead having eight electrically independent electrodes. Such systems are currently available from Medtronic, Inc., Advanced Neuromodulation Systems, Inc., and Advanced Bionics Corporation. Even though these implantable systems can treat chronic pain with a limited success rate, these systems have to be permanently implanted, have to be exchanged once the battery is depleted, or have to be recharged through an external battery charging system.
It is also well known in the art that ablating the affected area of the spinal cord can alleviate chronic pain on a long-term basis or even on a permanent basis. U.S. patent application Pub. No. 2005/0283148 to Janssen et al., and U.S. patent application Pub. No. 2005/0060006 to Pflueger et al. describe methods and devices for ablating nerve tissue. One means of ablating nerve tissue is through the use of RF energy delivered by electrodes implanted near the target tissue. Electrodes implanted within the spinal canal, for example, can be used to ablate tissues along the spinal cord to provide long term or even permanent relief to patients suffering chronic pain.
Such conventional methods and systems generally have been considered satisfactory for their intended purpose. However, pinpointing the exact location in the epidural space for ablation can be difficult when ablation electrodes are directed anatomically into the treatment location. Solutions to this problem have been developed to allow for directing ablation electrodes into place visually. Such visual techniques include guiding radio opaque ablation catheters fluoroscopically, or using optic fibers with cameras to visually guide the ablation electrodes into place.
However, even visual location techniques can fail to be successful or reliable. Physicians cannot always visually identify the precise location of the tissue which if ablated will alleviate the chronic pain. Guesswork is often involved and physicians may need to ablate large amounts of tissue in order to insure complete treatment of a small amount of target tissue. As a result, the target nerves are often ablated along with numerous otherwise healthy nerves. Unnecessary ablation of healthy nerves is detrimental because ablation can be permanent. There still remains a continued need in the art for a system and method that can reliably pinpoint the specific spinal nerve tissue for precise ablation. There also remains a need in the art for such a system and method that are inexpensive and easy to make and use. The present invention provides a solution for these problems.